css/css-writing-modes/reference/table-cell-002-ref.html

<!doctype html>
<html lang="en">
<meta charset="utf-8">
<title>CSS Writing Mode test reference</title>
<link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net/">
<meta flags="ahem">

<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
<style>
div {
  font: 50px / 50px ahem;
  color: green;

  max-height: 100px;
  writing-mode: vertical-rl;
  /* Doing this with a horizontal div and max-width ought to result in the same 100x100 green square,
     but font rasterisation may (and in practice does) result in different aliasing artifacts.
     Therefore I am using the same writing mode as the test,
     to make sure we get identically sharp/fuzzy edges on the same sides.
  */
}
</style>

<p>There should be a <strong>green square</strong> and <strong>no red</strong>.

<div>xx xx</div>

</body>
</html>